Background: The prevalence of increased oxidative stress and acute-phase inflammation in patients with chronic kidney disease (CKD) has not been thoroughly investigated.
Methods: Biomarkers of oxidative stress and acute-phase inflammation were measured in a cohort of 60 patients with stage 3-5 CKD compared to a healthy subject cohort. Levels of oxidative stress and inflammation were also compared to estimated glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) formula.
Results: All biomarkers of oxidative stress (plasma protein carbonyl group content, plasma free F2-isoprostane content, plasma protein reduced thiol content) and all markers of inflammation [C-reactive protein (CRP), interleukin-6 (IL-6)] differed significantly between CKD patients and healthy subjects. There was no significant relationship between estimated GFR and any oxidative stress or inflammation biomarker. CRP levels were higher in patients with known coronary vascular disease (CVD) and in patients not taking angiotensin II inhibitors. Plasma IL-6 levels were significantly higher in patients with known coronary vascular disease and lower in patients taking statins. Biomarkers of oxidative stress were significantly higher in patients with diabetes and hypercholesterolemia.
Conclusion: There is evidence of increased oxidative stress and acute-phase inflammation in patients with stage 3-5 chronic kidney disease compared to healthy subjects that does not closely correlate with estimates of GFR. Among CKD patients, inflammatory biomarkers correlate with known CVD and inversely correlate with the use of angiotensin II inhibitors and statins. A further increase in oxidative stress was noted in diabetic and hypercholesterolemic patients. Inflammation and oxidative stress may contribute to cardiovascular risk in CKD patients.